The present invention relates to a foaming device capable of generating foam by mixing a quantity of liquid with a volume of air, in accordance with the preamble of claim 1.
It is known that in the field of devices for generating foam by mixing a foam-generating liquid with air, the need to optimize foam formation is increasingly felt.
One solution currently used in the field of foam-generating devices, particularly devices using two pumping members (one for expelling a quantity of liquid and the other for compressing and expelling a volume of air), requires that the said devices be produced in such a way that they expel a constant rate of flow of air during the escape of the foam.
In this context, xe2x80x9crate of flow of airxe2x80x9d means the variation in the volume of air expelled as a function of the displacement of an air piston which deforms (compresses) the chamber in which the air to be expelled is contained.
The above solution has the disadvantage of expelling an airflow that does not completely mix with the liquid. In other words, at the beginning of the compression of the device, the airflow that invests the liquid is too great for the available liquid.
An example of a foam-generating device with an air chamber enclosed in a compressible bellows (shaped appropriately to ensure the escape of the air in a constant air/liquid ratio) is disclosed in U.S. Pat. No. 5,462,208.
The present invention addresses the problem of devising a foaming device that has structural and functional characteristics such as to satisfy the abovementioned requirements and at the same time obviate the problems discussed with reference to the prior art.
This problem is solved with a foaming device in accordance with claim 1, capable of generating foam by mixing a quantity of liquid with a volume of air.
Further characteristics, and the advantages, of the device according to the present invention will become clear in the following description of a preferred embodiment thereof.